1. Field of the Invention
The present invention relates to devices for applying chemical sealants to seams between adjacent sheets of flooring.
2. Description of the Prior Art
In the flooring trade sheets of flooring formed of linoleum and other thermoplastic or plastic composition materials are laid in relatively large sections, side-by-side and secured one by one with a chemical adhesive to a floor underlayment. The seams between adjacent sheets of flooring represent a particularly vulnerable location in the flooring installation. That is, although flooring installers attempt to abut adjacent sheets of flooring tightly against each other, there is always a seam between adjacent flooring sheets. Dirt and moisture can penetrate the seam and seep beneath the flooring sheets. This often results in a deterioration of the bond between the flooring and the underlayment. Such deterioration results in a separation of the flooring from the underlayment where the edges of the sheets of flooring abut.
To avoid these types of problems it is highly desirable for the seams between adjacent sheets of flooring to be sealed. Sealing can be performed by grooving the adjacent edges of the abutting sheets of flooring and filling the grove with a molten, thermoplastic sealant which bonds to the adjacent edges of the flooring and forms a seal when cool. This process is sometimes referred to as “hot welding”. Alternatively, a chemical sealant can be applied to the abutting edges of the adjacent sheets of flooring to seal them together. This process is sometimes termed “cold welding”. The sealing of adjacent sheets of flooring using chemical adhesives in this manner is widespread in this country, particularly in residential flooring installations. The chemical composition of flooring products utilized in residential installations lends itself to cold welding or chemical sealing with adhesive applied in liquid form at room temperature, rather than heat welding, due to the chemical composition of the flooring products typically utilized in residential installations.
A number of different seam sealing applicators have been devised to apply chemical adhesive sealants to the interfaces between abutting edges of sheets of flooring. Very typically, a flow or squeeze bottle of liquid adhesive will be equipped with a seam sealer applicator tip having an orifice through which the liquid chemical adhesive is directed into the seam between adjacent sheets of flooring. Several very popular seam sealing applicators of this type employ a fin or keel structure as a seam follower in order to ensure that the flooring installer is directing the chemical adhesive sealant directly into the seam between adjacent sheets of flooring, and not onto the adjacent flooring surfaces.
As the surfaces of flooring goods utilized in residential flooring have improved and become more durable, conventional seam sealing applicators have become less and less satisfactory. One very popular seam sealing applicator is formed with a plastic tip that narrows at its extremity and terminates in an orifice located above a small fin. The fin follows the abutting edges between adjacent sheets of flooring and serves as a wedge or plow to temporarily widen the gap between the abutting edges of flooring so as to allow the liquid sealants to flow down into the gap.
While this device is quite acceptable for many types of flooring, it has been found that the fin tends to break off when this applicator is utilized with the harder, more durable types of flooring now increasingly utilized in residential floors. Also, even when utilized on softer flooring materials, a great deal of pressure is required to maintain the fin in the crevice between the adjacent sheets of flooring. The discharge end of the tip is quite narrow, so that the surface of force application is quite small and is located down at the flooring surface. Downward force can therefore only be applied to the tip by pressing downward on the lower extremity of the tip with the index finger of one hand.
A constant application of pressure by an installer using the index finger of one hand is fatiguing and also exposes the installer's index finger to the caustic effect of the seam sealing adhesive. In addition, the bead of sealant created is typically inordinately wide, thus leading to an unsightly appearance of the flooring on the edges adjacent the seam interface.
Another popular type of seam sealer applicator has a metal tip that has a T-shaped configuration. A narrow slit is formed in the vertically oriented leg of the T-shaped tip. However, a great deal of downward force is required in order to force the vertical leg of the T-shaped tip into the crevice between the adjacent sheets of flooring. The tip is quite narrow so that all of this force must be applied using only the tip of the installer's index finger. This creates considerable fatigue. It also exposes the index finger to an excessive amount of caustic sealant chemicals. Furthermore, the metal flanges of the tip tend to scrape and gouge the surface of the flooring on both sides of the seam between the flooring sheets.
Another type of conventional seam sealer applicator employs a brass tip that also has a T-shaped configuration. The orifice opening for dispensing the sealants is in the vertical leg of the T-shaped tip. While this device is effective for properly dispensing sealants deep into the seam, it tends to be self-sharpening. That is, as the device is used the depending leg of the applicator tip becomes sharper and sharper and tends to cut too deeply into the material. Also, this device, like many other conventional seam sealer applicators, requires an inordinate, fatiguing amount of force applied by only the installer's index finger of one hand. As with other conventional devices that necessitate the application of force by an installer utilizing a single index finger, the installer's finger is exposed to the irritating adhesives employed in the sealants.